#include <string.h>
#include <stdio.h>

int main ()
{
	char a[10] = "aaaaaaa";
	char *b = "bb";
	strncat(a, b, 1);
	printf("a=== %s \n", a);		// output: aaaaaaab
	char c[10] = "ccccc";
	char d[4] = "ddd";
	strncat(c, d, strlen(d) + 1);
	printf("c=== %s \n", c);		// output: cccccddd
}